The present disclosure relates to a vibrator and an electronic device including the same.
A vibrator, a device converting electrical energy into mechanical vibrations using the principle of the generation of electromagnetic force, is mounted in a mobile phone, or the like, to be used for silently notifying a user of call reception. In addition, as the market for mobile devices such as a mobile phones and the like has rapidly expanded and various functions have been added to such mobile devices, mobile devices having small size and high quality have been required. In this situation, the need for developing vibrators having new structures capable of overcoming disadvantages of existing products and significantly improving quality has increased.
Further, as the release of smartphones onto the market has rapidly increased, a touchscreen scheme has been adopted, such that the adoption of vibration motors has increased in order to generate vibrations at the time of a touch interaction with such a smartphone. Performance particularly required in the vibrations at the time of a touch interaction with a touchscreen is as follows. First, as the number of vibrations generation at the time of the touch interactions has increased to be greater than that of vibrations generation at the time of call reception, operational lifespans of vibrators needs to be increased. Second, in order to increase user satisfaction when a user encounters vibrations at the time of the touch interaction, a response speed of the vibrations needs to increase in accordance with a speed of a touch interaction with the screen.
As a product capable of implementing the characteristics as described above, there is provided a piezo haptic actuator. Such a piezo haptic actuator uses the principle of a converse piezoelectric effect, which generates displacement of a piezo element when a voltage is applied thereto, and vibrational force is generated by allowing a weight of a mass body to move by the generated displacement.
A vibrator having this structure may be characterized in that a frequency bandwidth capable of obtaining vibrational force at a predetermined level or more is wider, such that stable vibration characteristics may be implemented, and vibrations having a low or high frequency rather than a single frequency may be variously used within a predetermined frequency range. In addition, since the rapid operation response characteristics may be implemented, such a piezo haptic actuator may be suitable for implementing haptic vibrations in mobile devices such as mobile phones, and the like.
Meanwhile, a piezoelectric element generating vibrations as described above is mounted on an elastic member to thereby vibrate, but when an external impact (particularly, in an axial direction) is applied thereto, the piezoelectric element may be floated or separated from the elastic member.
That is, the piezoelectric element formed of a ceramic material may be coupled to an elastic member formed of a metal material by an adhesive, but coupling force of the adhesive is not strong enough to resist excessive external impacts, such that the piezoelectric element may be separated from the elastic member.